Test No. 9: While System Is In Alarming Condition, Taillights Do Not Flash; Or When System Is Not Set, Taillights Stay On
WARNING: This page is about a different car, the 2002 Toyota Avalon. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
To flash the taillights, the theft deterrent ECU requests the body control ECU to activate the taillights across the multiplex communication bus. The taillights are controlled and monitored by the body control ECU. For testing procedures covering taillight system, see BODY CONTROL SYSTEMS - AVALON
article under COMMUNICATION DEVICES in ACCESSORIES & EQUIPMENT.